of Guides formed by Napoleon in Italy in 1796, which appears to have been a personal escort or body guard composed of men who knew the country. In the Belgian army of to-day the Guide regiments correspond almost to the Guard cavalry of other nations; in the Swiss army the squadrons of "Guides" act as divisional cavalry, and in this role doubtless are called upon on occasion to lead columns. The "Queen's own Corps of Guides" of the Indian army consists of infantry companies and cavalry squadrons. In drill, a "guide" is an officer or non-commissioned officer told off to regulate the direction and pace of movements, the remainder of the unit maintaining their alignment and distances by him. A particular class of guides are those employed in mountaineering; these are not merely to show the way but stand in the position of professional climbers with an expert knowledge of rock and snowcraft, which they impart to the amateur, at the same time assuring the safety of the climbing party in dangerous expeditions. This professional class of guides arose in the middle of the 19th century when Alpine climbing became recognized as a sport (see MOUNTAINEERING). It is thus natural to find that the Alpine guides have been requisitioned for mountaineering expeditions all over the world. In climbing in Switzerland, the central committee of the Swiss Alpine Club issues a guides' tariff which fixes the charges for guides and porters; there are three sections, for the Valais and Vaudois Alps, for the Bernese Oberland, and for central and eastern Switzerland. The names of many of the great guides have become historical. In Chamonix a statue has been raised to Jacques Balmat, who was the first to climb Mont Blanc in 1786. Of the more famous guides since the beginning of Alpine climbing may be mentioned Auguste Balmat, Michel Cros, Maquignay, J. A. Carrel, who went with E. Whymper to the Andes, the brothers Lauener, Christian Almer and Jakob and Melchior Anderegg. "Guide" is also applied to a book, in the sense of an elementary primer on some subject, or of one giving full information for travellers of a country, district or town. In mechanical usage, the term "guide" is of wide application, being used of anything which steadies or directs the motion of an object, as of the "leading" screw of a screw-cutting lathe, of a loose pulley used to steady a driving-belt, or of the bars or rods in a steam-engine which keep the sliding blocks moving in a straight line. The doublet "guy" is thus used of a rope which steadies a sail when it is being raised or lowered, or of a rope, chain or stay supporting a funnel, mast, derrick, &c.